The present application relates to a communication apparatus, and, more particularly, to a communication apparatus which performs near field communication with a non-contact card.
There has been proposed an application method that connects a television receiver (hereinafter called TV) to the Internet to allow a user to enjoy on-line shopping, which is utilized using a personal computer or the like, on the TV.
In this case, a card reader/writer (hereinafter called card R/W) which reads information from a non-contact card may be mounted in a remote controller for the TV. Then, the user needs to merely place a credit card made by a non-contact card over the remote controller to easily carry out a procedure for settlement for on-line shopping without performing an operation of entering a password, a card number and so forth.
To surely sense a non-contact card placed over the remote controller at an arbitrary timing, the card R/W needs to periodically execute a polling process of generating electromagnetic waves around to search for the non-contact card. If the polling process is performed always, the service life of the battery of the remote controller becomes shorter, making it necessary to frequently change the battery. Given that the non-contact card is driven by two alkaline batteries (capacity of 4000 mAh) and the drive voltage and drive current of the card R/W are 1.9 V and 100 mA, respectively, the battery life prolongs only 4000÷1.9÷=21 hours.
One solution to the problem proposed is to periodically shift the mode of the near field radio communication apparatus among three modes, an idling mode, a target operation mode and an initiator operation mode, and to permit the polling process to be performed only in the initiator operation mode (see Patent Document 1 (JP-A-2006-129498). Adapting the application described in the Patent Document 1 to the above-described TV remote controller makes it possible to shorten the time for the polling process, reduce power consumption and prolong the battery life.